Dragon Blod wine ??

[Tenbears]

I was preparing to make a batch of dragon blood. As I read the recipe It said to place ingredients in Primary, add yeast. Then stir vigorously every day to infuse Oxygen. Now I am a mead guy and we play by a somewhat different set of ruled. But correct me if I am wrong. Does yeast not multiply in the presence of Oxygen, and produce alcohol in it's absence. If I stir the must vigorously every day until it reaches a SG of 1.000 will the yeast not burn up the sugar reproducing rather than making any significant alcohol. was there a typo in the recipe or am I missing something here?

 

[Rodnboro]

The way I understand it is the yeast consumes sugar and the by product is alcohol. So, if you keep the yeast happy and multiplying with oxygen, you are making alcohol until the tolerance is achieved or until you run out of sugar.


Sent from my iPhone using Wine Making

 

[dangerdave]

In this case, I will refer to Wikipedia for a great expanation of the importance of oxygen in wine making...

"Yeasts are facultative anaerobes meaning that they can exist in both the presence and absence of oxygen. While fermentation is traditionally thought of as an anaerobic process done in the absence of oxygen, early exposure of the yeast to oxygen can be a vital component in the successful completion of that fermentation. This is because oxygen is important in the synthesis of cell "survival factors" such as ergosterol and lanosterol. These sterols are important in maintaining the selective permeability of the yeast cell membrane which becomes critical as the yeast becomes exposed to increasing osmotic pressure and levels of alcohol in the wine. As a waste product of its own metabolism, alcohol is actually very toxic to yeast cells. Yeast with weak survival factors and lacking sterols may succumb to these conditions before fermenting a wine to complete dryness, leaving a stuck fermentation."

Are we on the same page now, my friend?

 

[sour_grapes]

I am with you, Ten. Here is my mental picture: When you start fermentation, there is oxygen dissolved in the must. After pitching yeast, they function aerobically and reproduce exponentially. (A yeast cell gets a LOT more energy from sugar if it can metabolize it aerobically, but no alcohol is produced.)

After a while, the oxygen dissolved in the must has been used up. The yeast switch to anaerobic metabolism, and start producing alcohol.

If any oxygen is introduced, the yeast will gladly take it and use it for metabolism/energy production. However. the rate at which you can get O2 into the must by stirring is insignificant compared to the rate that the yeast use it up. Ergo, most of the metabolism of the sugars is done anaerobically, and we get wine to drink.

 

[bkisel]

Crap! Must you guys spoil it for me? Up until now I thought it was all magic! ...

 

[Arne]

Crap! Must you guys spoil it for me? Up until now I thought it was all magic! ...

You know it is the time of year when magic happens>>

Arne

 

[Tenbears]

Thanks Dave and Paul. I understood aerobic, and anaerobic fermentation, and how developing a strong colony of yeasties prior to anaerobic fermentation was critical. As a mead guy Oxygen is in part out enemy as mead is very sensitive to oxidation. I have always ensured fermentation to dryness by carefully setting starting SG and selecting a yeast for its tolerances. Both of your explanations combined make it easy to understand that the introduction of O2 throughout the fermentation process to serve both cycles of the yeast, allowing it to maintain a healthy colony, while at the same time insufficient O2 to supply the entire colony thus allowing it to become anaerobic and produce alcohol. Interesting this wine stuff, Back to the lab Dr. frankinstien

 

[Elmer]

I have stirred and then I have not stirred.

In both instances I ended up with wine!

 

[sour_grapes]

Personally, I am in the "no-stir" camp. Starve those little *******s of O2 and make them give me alcohol! ::

 

[Tenbears]

Personally, I am in the "no-stir" camp. Starve those little *******s of O2 and make them give me alcohol! ::

See! That's how I always felt, get them good and strong, Then work them to death. But I have drank Dragon Blood that a friend made by Danger Dave's recipe it was great, I did not want mess with perfection. If it works I don't mess with it. Even when I don't completely understand why.